U.S. Pat. No. 5,498,970 discloses a socket for temporary connection of a ball grid array (BGA) integrated circuit device to a test circuit. The socket has a pattern of contacts corresponding to a ball grid array of the integrated circuit device. Each of the contacts has a set of two cantilever arms and terminating in tips adapted to capture one solder ball of the ball grid array integrated circuit. A nest structure is provided for causing the each pair of tips to move between an open position in which the tips are spaced away from each other sufficiently for receiving the associated solder ball and a closed position in which the tips are resiliently forced to grasp the ball. The nest structure is made of a pair of opposed combs each having a number of parallel cantilever racks with spaced projections and assembled with each other so that the racks of two combs are positioned alternately. The assembled nest structure is mounted on the contacts so that each of the projections of one comb engages with one of the tips of the contact and each of the projections of the other comb engages with the other of the tips. This allows that, by the movement of the combs in opposite directions, the paired tips of each contact move away from each other to move between the open and closed positions. This action is performed by an operation mechanism made of two U-shaped brackets each having a cross piece and two upstanding arms extending substantially perpendicular to the cross piece. The two bracket are nested facing each other and have the arms pinned to each other at approximately their midpoints with a hole. The nested brackets are provided around the combs so that one longitudinal upper edge of each cross piece is brought into contact with an outer surface portion of the associated comb. Also, a rectangular top cover is placed on the brackets so that a bottom of the cover faces and contacts with opposite ends of the upstanding arms, away from the cross piece. This allows that, simply by depressing the top cover with a downward pressure, the brackets rotate to each other and to have the longitudinal upper edges of the cross pieces force the combs toward each other, which results in that the paired tips are moved to the open position. Then, simply by releasing the downward pressure, the paired tips spring back their free positions.
According to the conventional socket, the BGA circuit device is easy to be connected with the test circuit through a simple action. However, an open space on the BGA integrated circuit is restricted within the rectangular top cover. This in turn restricts the size of a heat sink mounted on the BGA for dissipation of heat generated at the testing BGA circuit device.